NEIGHBOURHOOD
The neighbourhood of a word is the set of all the words in the lexicon which are minimally different from it. The term is usually applied to written forms but has also been used in theories of spoken word recognition. In theory, a neighbourhood includes words that are different by one letter, regardless of the position of the letter: on this analysis, REAP, BEAD, REED and ROAD are neighbours of READ. However, the term is often restricted to words which differ in their initial letter, initial digraph (TH-, SH-) or initial consonant cluster (PL-, BR-). For READ, it would include LEAD, BEAD, HEAD, DEAD etc. Within a neighbourhood, there are friends: words which share the same rime as well as the same spelling (the verb LEAD, BEAD). There are also enemies: words with the same spelling but a different rime (HEAD, BREAD, DEAD, the noun LEAD).
The neighbourhood concept serves to identify words which are in competition with each other by virtue of similarity of form. The sight of the word read on the page activates not only READ but also neighbours which form close matches to the target.
There is evidence that the time it takes to recognise a given word is affected by the size of its neighbourhood and the number of friends and enemies it possesses. Thus, recognition of a word like READ will be slowed by the existence of friends such as BEAD and particularly by the existence of enemies such as DEAD, HEAD, BREAD etc. By contrast, words like FEETor SIDE are recognised rapidly because they have few friends and no enemies.
The situation is complicated by the need to take account of the possible effects of frequency. A word such as HAVE has no friends and a number of enemies (CAVE, WAVE, RAVE, SAVE etc.) but happens to be a very frequent item. Some accounts therefore represent neighbourhood effects in terms of the frequency of the target word in relation to the accumulated frequencies of its neighbours. There is some disagreement between experimenters who have found that delayed recognition correlates with neighbourhood density (number of neighbours) and others who suggest that it correlates with total neighbourhood frequency.
In the Neighbourhood Activation Model, the speed with which a word is matched to a form on the page is determined by the probability that it, rather than its neighbours, is the correct choice. A formula has been devised to calculate this neighbourhood probability: the frequency of a given word is divided by the sum of frequencies of the entire neighbourhood.
It has been demonstrated that a sequence like GOPE (friendly neighbours in HOPE, ROPE) is identified as a non-word more rapidly than a sequence like HEAF (conflicting neighbours in LEAF, DEAF). This challenges the idea that reading non-words involves simply applying rules based on standard sound-spelling relationships. One solution is to assume that these rules include all possible interpretations of a particular letter or digraph (-EA- being recognised as potentially both /i:/ and /e/). Another approach, sometimes represented as an alternative to a neighbourhood account, is analogy theory, which suggests that words are interpreted phonologically by analogy with others, perhaps mainly on the basis of their rime.
See also: Analogy model, Competition, Rime
Further reading: Harley (2001: 182–8); Luce et al. (1990)
